Adam Is National Geographic's Expert on Nature's Circles

March 25, 2013

John Adam

Mother Nature may not produce perfect circles, but she sure does produce beautiful ones. That's the message from Old Dominion University mathematician John Adam, whose commentary was featured in a Pi Day report on the National Geographic Daily News website.

Pi Day is celebrated each March 14 because the date corresponds to the first three digits of pi - 3.14. Pi is the mathematical constant stating the ratio of a circle's circumference to its diameter.

National Geographic sought out Adam as an expert on circles in nature, largely on the strength of his book "Mathematics in Nature: Modeling Patterns in the Natural World" (Princeton University Press, 2003). Adam's nature photography also has been broadly published in books and magazines, and on the Internet.

For the National Geographic report, an interview with him is matched up with color photos of the rings of Saturn, a ripple on a pond, a rainbow and a cross-section of a plant stem.

"The closest thing to perfect circles in nature is probably circular wave patterns on a pond or puddle after a raindrop falls on it," Adam is quoted as saying. Even when a noncircular object is thrown into water, the resulting ripples will form in concentric circles, the article notes. Initially, the ripples expand accordingly to the object's shape, but as they spread farther outward, curves fill in the uneven spaces, leaving the ripples to morph into circular shapes.

Adam told National Geographic that these ripples and rainbows are probably the first two images that come to mind when thinking of circular patterns in nature.

Adam, who received a Ph.D. in theoretical astrophysics from the University of London in 1975, is the author of approximately 100 papers in several areas of applied mathematics and mathematical modeling. In addition to "Mathematics in Nature," he is co-author of "Guesstimation: Solving the World's Problems on the Back of a Cocktail Napkin" (Princeton, 2008) with Lawrence Weinstein of the ODU physics faculty. More recently, Adam has authored "A Mathematical Nature Walk" (Princeton, 2009) and "X and the City: Modeling Aspects of Urban Life" (Princeton, 2012).